Commutation of currents in armatures of dynamos.



PATENTED JAN. 29, 1907.

E. ARNOLD J. L. LA COUR. OOMMUTATON OF GURRBNTS IN ARMATURES OF DYNAMOS.

APPLICATION FILED DEO,16, 1904.

ENGELBEET ARNOLD, or KARLSRUHE, GERMANY, AND lJENS LASSEN LA coun, or EDINBURGH-SCOTLAND.

- COMMUTATION OF-CURRENTS IN ARMATURS rOF DYNMOS.

Specification of Letters "Patent,y

Patented aan. 29, 19er.

Appunti@ ned December 16,1904. sain No. 237.1571.

To a/ZZ whom it may concern:

' Be it known that we, ENGELBERT ARNOLD,

of Karlsruhe, Germany, and JENS LASSEN LA COUR, of Edinburgh, Scotland, have invented certain new and useful Improvements inl Commutation of Currents in Armatures of Dynamos, of which the following is a specilication.

The better to procure the commutation of electric currents in dynamos itis frequently advantageous to connect by resistances the segments of the commutatore or the seg-' This ments of the auxiliary commutatore.

vis shown by the alternating-current commutators of A. I-Ieyland, by the' commutator of Seidener, and by the commutator described in the German Patent No. 156,959. The construction'al arrangement of these resistances involves great difiiculties.

, is a diagram similar-to Fig. 1, but showing- The avoiding of suchconstructional dithculties is among the purposes of the present lnvention.

The resistances are inser-ted into insulating layers placed between the commutator- .bars Suchresistances consist of thin metallic plates, metallic tissue, or metallic ysolutions which are painted in broad'stripes upon the insulating material.

Figure 1 is a diagram` showing the application of resistances to an armature-winding according to the present invention. Fig. 2

another brush position; and Fig. 3 is a diagram-showing the application of the invention to `a wave-winding.

The equipotential connections incontinuous-current dynarnos must have jan electric resistance as .lowas possible and must serve to prevent sparking due to lack of symmetrv in the winding or in the magnetic eldgbiit the foregoing resistance connections musthave so-.great an electric resistance that the additional-currents due to thec'ommutation of the armature-.windings will remainbelow any admissible limit. f On the other hand, the. electric resistances -above referred to must be so low that in the winding the commutator-bars whereof are Inot touched by the brushes current'shall still be present.

Fig. 1 shows `three closed armature-windings A A2, andAa. Of these, A is connected to the segments HK', .A2 tothe segments K2,

not allowed to touch more-than three segments. rIherefore its breadth is somewhat and A3 to the segments K3. The' brush B is/ smaller than double the Abreadth of a segment. In the position shown in Fig. 1 coil S2 of winding A2 is in commutation. The commutating-current must flow through the two resistances 1. vHence'its intensity is limit-ed by these resistances.l Whilethe coil S2 has been particularly mentioned as being short-circuited, it will of course be understood that the coils lS andS3 are short-circuited at the same time. In vthis position, however, A2 is not switched off, as is done by the ordinary Weston windings, because current .flows to the brush B from the winding A2 through a great number of resistances 1*, which connect the three windings in 'multiple circuit. y the three coils S, S2, and Sspconnected in multiple circuit-by the resistances 7," these i 4coils must-be located in the .same slots as with the Heyla-nd commutator.

Fig. 2 represents the da am of a triplyclosed loop-winding for a ierent position of the commutator relative tothe brushes.- Here the letters denote thesame 'parts as in Fi 1.; B nd two resistances r. i In this position the three windings A', A2, and Aaall get current from the brush B.

Fig. 3 representsthe diagram of that part of a triply-closed. wave-winding which lies under -blmshesV having thesame polarity. The letters signifythe same as in the forego- Whcre a Wave-Winding is ernnumber ofpole distances, which is the usual arrangement, some of the armature-coils will be closed bybtwobrushes and the paralleling connection'whichjoins them. This will resultin destroying the effect of the resistances 1'." This willl be seen upon an-inspection of Fig. 3, which Will reveal that the The coils S areclosed bythe brush,A

brushes B B2 B3 of the same polarity touch.

the segments K K2, each pair vof v vhich is connected ,to the same windings, One or `more.armature-coils, therefore, are connected 'by the' brushes. In these coils electroroo motive force-is induced in continuous-curmutator.

rent dynamos by the stra-y iield of the slots and in alternating-current dynamos by the pulsations of the main eld. To obviate the eiiect on the resistances as above outlined,`

devices for producing electromotive force counter to that generated in the closed coils are to be inserted in the connections between the brushes of like polarity, so th at .the resulting current will be zero. f

In the manner described with multiple closed unsymn'ietric wave-windings as many brush-holder pins as desirable may be employed, so that we obtain av narrower com `With alternating-current cornmutator dynanios the electromotive force in the outer connections between the brushes of same polarity are most simply produced in] the following way: In the'said connections is inserted a number of stator-windings as great :as that of rotor-windings which lie between the brushes. The before-mentioned statorwindings should lie in the same held as the rotor-windings. By these means the pulsations of the main field of the dynainos willvv better commutation is as well `adapted forv ordinary continuous -current dynamos of high voltage and high number of revolutions as for single and multiphase commutator motors, generators, and converters. With continuous-current dynamos in the connections between the brushes accumulators of the desired voltage may be placed. This arrangement will, however, not be of great practical importance.

The present invention is thus an appliance for the commutation of current in dynamos,

this appliance consisting of a combination of an n times-closedy parallel winding with resistances which connect these n windings together. as shown, between the segments lof the commutator or be arranged in any` manner already known exterior to the commutator. In the latter case they` can be constructed of metallic wire. l

These resistancescan be placed,

What we claim as our invention, and desire to secure by Letters Patent of the United States, is-

1. The combination with an armaturewinding, consisting of a plurality of parallel sections, of a commutator, the said sections being connected to adiacent segments of said commutator, resistances connecting tne said sections., and brushes of a width not greater than the combined wii'lths of a number of commutator-segments equal "toone less than the number of armature-sections, bearing upon said commutator, substantially as described. l

2. The combination with a wave-winding for an armature, said winding consisting of a plurality of parallel sections, 'of a commutator, the said sections being connected to adjacent segments'of said commutator, resistances connecting the said sections, brushes of a width not greater than the combined widths ofk a number of commutatorsegments equal to one less than the number of armature-sections, bearing upon said commutator, connections external to the armature between brushes of like polarity, and means for introducing electromotive force in said connections, substantially as described.,

3. The combination with a wave-winding' for Aan armature, said winding consisting of a plurality of parallel sections, of a commutator, the said sections being connected to adjacent segments of said commutator, resistances connecting the said sections, brushes of a width not greater than the combined widths of a number of commutator-segments equal to one less than the number of armature-sections, bearing upon said commutator, connections external to the armature between brushes of like polarity, and coils inserted in said connections, said coils being adapted to have generated in them electromotive forces of the same values as are gen- ICO erated in the corresponding coils of the armature between the brushes, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

ENGELBERT ARNOLD. L .TENS LASSEN LA COUR. Witnesses for Engelbert Arnold WOLDEMAR HAnr'r, HERY I-IAsPERj v Y Witnesses for JensLassen la Cour:

JAMES PHILLIPS, GEORGE 'BRAm 

